This invention relates to fiberglass utility poles such as may be used in the mounting of luminaires, signs and the like, and particularly to a novel construction thereof and the method of forming such pole construction. Fiberglass pole constructions in which various layers of fiberglass are covered or otherwise filled with curable plastic resin overlayed or wrapped around one another are know. Poles constructed in this manner may be used in place of wooden, aluminum or steel poles and offer considerable advantages thereover including lower weight, easier installation, lower cost, vibration dampening and greater life expectancy. Such poles also by their nature are resistive to rain, wind, salt and other chemical sprays, exposure to the sun and may be directly implanted in the soil without need of preservative impregnation or any special protective covering. Of course, if it is not desired to implant the fiberglass pole, it may be mounted above ground simply by using conventional supports to facilitate such.
An example of such a fiberglass pole construction is shown in U.S. Pat. No. 3,896,858 issued July 29, 1975. In such regard the above patent citation and discussion constitutes applicant's Prior Art Statement and accordingly a copy of such patent is enclosed with the instant application.
Despite the existence of fiberglass poles of the above-indicated type, it would be desirable to be able to provide fiberglass pole constructions having increased resistance to bending and deflection when mounted. It would also be desirable to have such a pole in which areas thereof have particular strength characteristics built therein so as to better facilitate the mounting of signs, luminaires and the like. Accordingly, a primary object of the present invention is the provision of a fiberglass pole construction in which the strength characteristics thereof and particularly its resistance to deflection, when mounted, can be tailor made for particular end use applications.
A further object of the present invention is the provision of a fiberglass utility pole of the above-indicated type in which there are component layers arranged with respect to each other and with regard to the pole axis so as to contribute to such desired strength characteristics.
A further object of the present invention is the provision of a novel method of forming the pole construction of the subject invention such that the pole may be readily formed in an efficient and low-cost manner.
These and other objects of the present invention are accomplished by the provision of an elongated, hollow tapered pole of composite structure having integrally resin bonded inner, outer and intermediate layers wherein the inner and outer layers are generally spirally laid wraps of substantially resin impregnated glass fiber ribbon extending the entire length of the pole with the intermediate layer disposed therebetween, said intermediate layer including a plurality of resin bonded sublayers, each of said sublayers including separate strips of unidirectional glass fibers, each aligned parallel to the longitudinal axis of the pole. Additionally the intermediate sublayers are longitudinally staggered with respect to each other such that all of the strips do not extend the entire length of the pole such that those areas having a greater number of sublayers will accordingly be strengthened in accordance with the teachings of the present invention.
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.